The subject matter described herein relates generally to electrified rail systems.
Known electrified rail systems include rail vehicles that are powered by electric current. The rail vehicles may receive current from a utility, such as an electric utility or company that generates, transmits, and/or distributes electric current to a general population. The current is supplied along feeder lines or cables that deliver the current to substations located along a track on which the rail vehicles travel. The substations supply the current to overhead catenaries that transmit the current to the rail vehicles.
One problem with some known electrified rail systems is that the available supply of electric current may not adapt as the demand for the current changes. For example, the supply of current may not change in response to changes in the rail traffic throughout a day. As a result, the supply of current may be greater than the need of the rail vehicles or the supply may be unable to meet the need for electric current to power the rail vehicles.
Another problem with some known electrified rail systems is the inability to introduce additional sources of current for the rail vehicles. For example, some systems may be limited to supplying current from existing utilities rather than allowing other sources of current to supply current to the rail vehicles.
Additionally, some electrified rail vehicles create electric current that is fed back to the sources of current that power the vehicles. For example, some rail vehicles include regenerative braking systems that create electric current when the rail vehicles slow down. The magnitude of the regenerative current that is created by the vehicles may depend on number of vehicles, the kinetic energy of the vehicles, and the like. The utilities that receive the regenerative current may have limits on the regenerative current that can be received from the rail vehicles. For example, during periods of relatively low traffic density of rail vehicles, the utility that supplies power to the rail vehicles may be unable to accept most or all of the regenerative current. As a result, the rail vehicles can have limits on the maximum speeds at which the rail vehicles travel in order to avoid overloading the utilities with regenerative current.
The speed at which electrified rail vehicles operate may be based on control signals that are transmitted to the rail vehicles. The control signals are used to speed up or slow down the rail vehicles. Electronic hardware is required to transmit, receive, and interpret the control signals. This electronic hardware is in addition to the other hardware and components of the rail vehicles. As a result, the electronic hardware used to transmit, receive, and interpret the control signals adds to the cost of providing and/or maintaining the rail vehicles.
A need exists to provide assemblies, systems, and/or methods that control the supply of electric current to electrified rail vehicles and that address one or more of the shortcomings of some known electrified rail systems described above.